scholarly journals Assessment of the impact of 10-day intermittent hypoxia on the autonomic control measured by heart rate variability

2018 ◽  
Vol 105 (4) ◽  
pp. 386-396 ◽  
Author(s):  
ZZ Taralov ◽  
KV Terziyski ◽  
PK Dimov ◽  
BI Marinov ◽  
SS Kostianev

Purpose The purpose of this study is to establish the alterations in the activity of the autonomic nervous system (ANS) via heart rate variability (HRV) in subjects exposed to 1 h of exogenous hypoxia for 10 consecutive days. Methods Twelve healthy non-smoker males at mean age of 29.8 ± 7.4 (mean ± SD) breathed hypoxic air delivered through hypoxicator (FiО2 = 12.3% ± 1.5%) for 1 h in 10 consecutive days. Pulse oximetry and electrocardiography were monitored during the visit and HRV was calculated for the entire 1-h hypoxic period. Results Comparing the last hypoxic visit to the first, subjects had higher standard deviation of normal-to-normal interbeat intervals (SDNNs) (65.7 ± 32.5 vs. 81.1 ± 32.0 ms, p = 0.013) and root mean square of successive R–R interval difference (RMSSD) (58.1 ± 30.9 vs. 76.5 ± 34.6 ms, p = 0.029) as well as higher lnTotal power (8.1 ± 1.1 vs. 8.5 ± 0.9 ms2, p = 0.015) and high frequency (lnHF) (6.8 ± 1.3 vs. 7.5 ± 1.2 ms2, p = 0.05) and lower LF/HF (2.4 ± 1.4 vs. 1.5 ± 1.0, p = 0.026). Changes in saturation (87.0 ± 7.1 vs. 90.8 ± 5.0%, p = 0.039) and heart rate (67.1 ± 8.9 vs. 62.5 ± 6.0 beats/min, p = 0.040) were also observed. Conclusions Intermittent hypoxic training consisting of 1-h hypoxic exposure for 10 consecutive days could diminish the effects of acute exogenous hypoxia on the ANS characterized by an increased autonomic control (SDNN and total power) with augmentation of the parasympathetic nervous system activity (increased RMSSD and HF and decreased LF/HF). Therefore, it could be applied as a pre-acclimatization technique aiming at an increase in the autonomic control and oxygen saturation in subjects with upcoming sojourn to high altitude.

1996 ◽  
Vol 91 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Peter Walter Kamen ◽  
Henry Krum ◽  
Andrew Maxwell Tonkin

1. Time domain summary statistics and frequency domain parameters can be used to measure heart rate variability. More recently, qualitative methods including the Poincaré plot have been used to evaluate heart rate variability. The aim of this study was to validate a novel method of quantitative analysis of the Poincaré plot using conventional statistical techniques. 2. Beat-to-beat heart rate variability was measured over a relatively short period of time (10–20 min) in 12 healthy subjects aged between 20 and 40 years (mean 30 ± 7 years) during (i) supine rest, (ii) head-up tilt (sympathetic activation, parasympathetic nervous system activity withdrawal), (iii) intravenous infusion of atropine (parasympathetic nervous system activity withdrawal), and (iv) after overnight administration of low-dose transdermal scopolamine (parasympathetic nervous system augmentation). 3. The ‘width’ of the Poincaré plot, as quantified by SD delta R—R (the difference between successive R—R intervals), was determined at rest (median 48.9, quartile range 20 ms) and found to be significantly reduced during tilt (median 19.1, quartile range 13.7 ms, P < 0.01) and atropine administration (median 7.1, quartile range 5.7 ms, P < 0.01) and increased by scopolamine (median 79.3, quartile range 33 ms, P < 0.01). Furthermore, log variance of delta R—R intervals correlated almost perfectly with log high-frequency (0.15–0.4 Hz) power (r = 0.99, P < 0.01). 4. These findings strongly suggest that the ‘width’ of the Poincaré plot is a measure of parasympathetic nervous system activity. The Poincaré plot is therefore a quantitative visual tool which can be applied to the analysis of R—R interval data gathered over relatively short time periods.


Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Amanda C Costa ◽  
Ana Gabriela C Silva ◽  
Cibele T Ribeiro ◽  
Guilherme A Fregonezi ◽  
Fernando A Dias

Background: Stress is one of the risk factors for cardiovascular disease and decreased heart rate variability is associated to increased mortality in some cardiac diseases. The aim of the study was to assess the impact of perceived stress on cardiac autonomic regulation in young healthy volunteers. Methods: 35 young healthy volunteers (19 to 29 years old, 6 men) from a Brazilian population were assessed for perceived stress by the translated and validated Perceived Stress Scale (PSS, 14 questions) and had the R-R intervals recorded at rest on supine position (POLAR RS800CX) and analyzed (5 minutes, Kubius HRV software) by Fast-Fourier Transform for quantification of Heart Rate Variability (HRV). Results: Average data (±SD) for age, heart rate, BMI, waist circumference and percentage of body fat (%BF) were: 21.3±2.7 years; 65.5±7.9 bpm; 22.3±1.9 Kg/m 2 ; 76.0±6.1 cm and 32.1±6.6%; respectively. The mean score for the PSS-14 was 23.5±7.2 and for the HRV parameter as follow: SSDN=54.8±21.2ms; rMSSD=55.9±32.2ms; low-frequency (LF)= 794.8±579.7ms 2 ; High-frequency (HF)= 1508.0±1783.0 ms 2 ; LF(n.u.)= 41.1±16.2; HF(n.u.)= 58.9±16.2; LF/HF=0.89±0.80 and Total power (TP)= 3151±2570ms 2 . Spearman nonparametric correlation was calculated and there was a significant correlation of PSS-14 scores and LF (ms 2 ) (r=−0.343; p= 0.044). Other HRV variables did not shown significant correlation but also had negative values for Spearman r (TP r=−0.265, p=0.124; HF r=−0.158; SSDN r=−0.207; rMSSD r=−0.243, p=0.160). LF/HF and LF(n.u.) did not correlate to PSS-14 having Spearman r very close to zero (LF/HF r=−0.007, p=0.969; LF(n.u.) r=−0.005, p=0.976). No correlation was found for HRV parameters and BMI and there was a trend for statistical correlation of %BF and LF (ms 2 ) (r=−0.309, p=0.071). Conclusions: These data demonstrate a possible association of perceived stress level and HRV at rest. Changes in LF can be a consequence of both sympathetic and parasympathetic activity, however, analyzing the other variables HF, TP, SSDN and rMSSD (all negative Spearman r) and due to the lack of changes in LF/HF ratio and LF(n.u.) we interpret that increased stress may be associated to decrease in overall heart rate variability. These changes were seen in healthy individuals and may point out an important mechanism in cardiovascular disease development.


2015 ◽  
Vol 28 (3) ◽  
pp. 627-636 ◽  
Author(s):  
Gustavo Henrique de Oliveira Mondoni ◽  
Luiz Carlos Marques Vanderlei ◽  
Bruno Saraiva ◽  
Franciele Marques Vanderlei

AbstractIntroduction It is known that physical exercise is beneficial and precipitates adjustments to the autonomic nervous system. However, the effect of exercise on cardiac autonomic modulation in children, despite its importance, is poorly investigated.Objective To bring together current information about the effects of exercise on heart rate variability in healthy and obese children.Methods The literature update was performed through a search for articles in the following databases; PubMed, PEDro, SciELO and Lilacs, using the descriptors “exercise” and “child” in conjunction with the descriptors “autonomic nervous system”, “sympathetic nervous system”, “parasympathetic nervous system” and also with no descriptor, but the key word of this study, “heart rate variability”, from January 2005 to December 2012.Results After removal of items that did not fit the subject of the study, a total of 9 articles were selected, 5 with healthy and 4 with obese children.Conclusion The findings suggest that exercise can act in the normalization of existing alterations in the autonomic nervous system of obese children, as well as serve as a preventative factor in healthy children, enabling healthy development of the autonomic nervous system until the child reaches adulthood.


2007 ◽  
Vol 16 (4) ◽  
pp. 336-342
Author(s):  
Nicolas Olivier ◽  
Renaud Legrand ◽  
Jacques Rogez ◽  
FX Gamelin ◽  
Serge Berthoin ◽  
...  

Objective:To analyze the consequences on heart rate variability (HRV) of a hospitalization period due to surgery of the knee in sportsmen.Patients:Ten soccer players who had undergone knee surgery took part in this study.Design:HRV was measured before and after hospitalization within a 7-day interval.Results:After the hospitalization phase, heart rate at rest increased significantly (3 beats/minute). A significant decrease of 7% in the cardiac inter beat interval (R-R interval), P < 0.05 and a 66% decrease in total power spectral density: −66%, P < 0.05 were observed. The disturbance of the autonomic nervous system could be due to a variation in cardiac vagal activity resulting in a 64% decrease in the high frequencies (P < 0.05). This variation was not associated with a modification in normalized markers (LFn.u., HFn.u.) and LF/HF ratio (P > 0.05).Conclusion:In sportsmen, a hospitalization period led to an increase in resting heart rate and was associated with a disturbance of the autonomic nervous system.


2014 ◽  
Vol 32 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Camila Balsamo Gardim ◽  
Bruno Affonso P. de Oliveira ◽  
Aline Fernanda B. Bernardo ◽  
Rayana Loch Gomes ◽  
Francis Lopes Pacagnelli ◽  
...  

OBJECTIVE:To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior.DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review.DATA SYNTHESIS: The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals.CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group.


2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Robert Podstawski ◽  
Michał Boraczyński ◽  
Danuta Nowosielska-Swadźba ◽  
Danuta Zwolińska

Summary Study aim: Regular exercise training is thought to modify cardiac autonomic control. One of the body’s responses to training stimuli is heart rate variability (HRV). The use of HRV in the management of sport training is a common practice. The objective of the present study was to assess the impact of the physical activity level on HRV of 1st league national volleyball players prior to and during the competition period. Materials and methods: The study involved 11 players whose HRV was evaluated during the two analysed training periods. Selected indicators of spectral analysis (total power, %VLF, % LF, % HF powers, LF n.u, HF n.u, and LF/HF powers) as well as time analysis (HR, RR, RMSSD, NN50) were assessed on the basis of recordings. Results: The studies conducted in the pre-competition and competition periods showed significant differences in the parameters of spectral VLF% analysis and time NN50 analysis. In the competition period, a significant increase in VLF [%] may be the result of increased psycho-physical arousal, when compared to the pre-competition period. ] Conclusions: Resting bradycardia, assessed on the basis of time analysis indicators, may be the result of internal changes in the sinus node, which reflects the impact of long-term training on the cardiac conduction system. A high level of physical activity of volleyball players in the tested periods could have contributed to a reduction in vagal tone and a shift in the balance of the autonomic nervous system in the direction of the sympathetic system, which may be the result of overtraining


Author(s):  
O.V. Kiyok ◽  
V.M. Pokrovskiy

The impact of specific factors on students during workshop practice results in tension of regulatory and adaptive mechanisms. This fact can be estimated according to the heart rate variability (HRV). It is of the integral indicators reflecting all mechanisms of cardiac regulation. The aim of the study is to assess students’ adaptive capacity during workshop training based on HRV. Materials and Methods. The authors divided 30 students into two groups: a group of less adapted and a group of more adapted students. J. Strelau’s theory on temperament and H. Eysenck's personality types were used for the purpose. The authors studied heart rate variability at the beginning and at the end of workshop practice. Statistika 6.0 for Windows was used to process the results. Results. The authors distinguished differences in HRV in two study groups. Before practice, the regulatory system tension index was 479.64 in the group of less adapted students. It was 106.86 in the group of more adapted students. The total power (ms2) indicating adaptive capacity was by 80.9 % higher in more adapted students. After workshop practice, changes in the tonus of the autonomic nervous system were observed in both study groups. However, in the group of less adapted students, indicators confirming sympathicotonia and a decrease in heart rate variability changed to a greater degree. Thus, tension index in the group of more adapted students increased by 46.7 %, and in the group of less adapted students – by 209.9 %. The authors also observed a decrease in the total power: in more adapted students by 51.3 %, and in the less adapted students by 54.3 %. Results. Analysis of HRV showed a more evident adverse influence of workshop practice on less adapted students. Keywords: students, workshop practice, heart rate variability. Воздействие специфических факторов на учащихся при прохождении производственной практики приводит к напряжению регуляторно-адаптивных механизмов, что можно оценить по вариабельности ритма сердца (ВРС) – одному из интегральных показателей, отражающих механизмы сердечной регуляции на всех уровнях. Цель исследования. Оценить адаптивные возможности учащихся при прохождении производственной практики по показателям ВРС. Материалы и методы. У 33 учащихся, разделенных согласно теории Я. Стреляу и в соответствии с психологическими типами личности по Айзенку на группы менее адаптированных и более адаптированных, изучили вариабельность ритма сердца в начале и конце производственной практики. Для обработки результатов исследования применяли программу Statistika 6,0 for Windows. Результаты. Установлены различия ВРС в двух исследуемых группах. До практики индекс напряжения регуляторных систем (ИН) в группе менее адаптированных составил 479,64, в группе более адаптированных учащихся – 106,86. Общая мощность спектра ТР (мс2), свидетельствующая об адаптивных возможностях, у более адаптированных учащихся была выше на 80,9 %. После производственной практики изменения тонуса вегетативной нервной системы отмечены в обеих исследуемых группах. Однако в группе менее адаптированных учащихся показатели, свидетельствующие о симпатикотонии и уменьшении вариабельности ритма сердца, изменились в большей степени. Так, ИН в группе более адаптированных учащихся увеличился на 46,7 %, а в группе менее адаптированных – на 209,9 %. Отмечено уменьшение общей мощности спектра: у более адаптированных на 51,3 %, у менее адаптированных на 54,3 %. Выводы. На основании анализа ВРС показано более выраженное неблагоприятное влияние производственной практики на менее адаптированных учащихся. Ключевые слова: учащиеся, производственная практика, вариабельность ритма сердца.


Biofeedback ◽  
2013 ◽  
Vol 41 (3) ◽  
pp. 136-143 ◽  
Author(s):  
Leah Lagos ◽  
James Thompson ◽  
Evgeny Vaschillo

Heart rate variability (HRV) biofeedback (BFB) can be used to reduce activation of the sympathetic nervous system (SNS) and increase activation of the parasympathetic nervous system (PNS). A growing body of research suggests that increased arousal of the SNS contributes to the sustained state of postconcussion syndrome (PCS). It has also been postulated that underactivation of the PNS may also play a role in the postinjury state of autonomic dystonia, wherein the autonomic nervous system is in a state of imbalance and does not return to normal. In addition to autonomic imbalance, patients who are generally advised not to engage in physical exertion until asymptomatic from concussion, are known to experience secondary symptoms of fatigue and reactive depression. Recent research has established that such symptoms can delay the recovery from concussion indefinitely. By addressing both autonomic dysfunction and the secondary symptoms of depression and anxiety, HRV BFB may be an effective treatment for PCS by strengthening self-regulatory control mechanisms in the body and improving autonomic balance. Recent studies have suggested that HRV BFB has a positive impact in reducing stress and anxiety among athletes, and concussed athletes with higher perceived control over their symptoms have been shown to have faster recoveries post-injury. The primary purpose of the following case study was, therefore, to assess the feasibility of implementing HRV BFB with a concussed athlete suffering from postconcussion syndrome (PCS). The second objective was to prospectively examine the impact of ten weeks of HRV biofeedback on refractory postconcussion symptoms. During this pilot case study, the athlete attended 10 weekly sessions of HRV BFB, according to the protocol set forth by Lehrer, Vaschillo, and Vaschillo (2000). After 10 weeks of HRV biofeedback, the athlete exhibited clinically significant improvements in total mood disturbance, postconcussion symptoms, and headache severity. The results suggest that HRV BFB may be a useful adjunctive treatment for PCS, associated with increases in HRV and enhanced cardiovagal activity. Given these findings, a randomized controlled trial is warranted.


2021 ◽  
Vol 31 (Supplement_2) ◽  
Author(s):  
Joaquim Pereira ◽  
Ana Santos ◽  
Telmo Pereira

Abstract Background The practice of high perfomance sports leads to alterations of the autonomic nervous system (ANS). The study of heart rate variability (HRV) resorting to the electrocardiogram (ECG) is a practical, efficient and non invasive tool that allows the monitorization of the cardiac-autonomic function in high perfomance athletes, exposing the physiological adaptations to repeated and intense physical exercise. To evaluate the resting heart rate variability of futsal players resorting to the electrocardiogram during the pre-season and competitive season. Methods The sample used in this study was composed of fifteen male futsal athletes, subjected to a resting electrocardiogram in supine position with the duration of 6 minutes, at two different moments. Results From the first to the second record heart rate variability, it was observed a significant decrease in heart rate from 66.53 ± 10.39 bpm to 61.50 ± 11.14 bpm (P &lt; 0.05) and the indexes related to the activity of the parasympathetic nervous system (PNS), RMSSD, pNN50, HFnu did not present statistical significance (P &gt; 0.05) despite the verified increased of absolute values from the first to the second evaluation. Conclusions We were able to observe a decrease in heart rate (HR), as well as, a tendency for elevated parasympathetic indexes and a vagal predominance from the first to the second moment of evaluation. The monitorization of heart rate variability can be useful to identify adaptations to competitive loads and, thus, planning adequate training loads for each athlete, avoiding the occurrence of lesions and fatigue and allowing an improvement in performance.


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